Method of duplicating a hologram and hologram optical element

Abstract

Here discloses a method for duplicating a hologram and a hologram optical element. The method comprises: preparing a master with a master hologram; preparing a sample with coated photoalignment material layer above the master; and irradiating a recording light through the sample to the master, so that at least one portion of the recording light is reflected by the master as an object light carrying the master hologram information, and so that the object light and the recording light are interfered at the photoalignment material layer to produce a duplicated hologram in the photoalignment material layer.

1 . A method for duplicating a hologram, comprising:
 preparing a master with a master hologram;   preparing a sample with a coated photoalignment material layer above the master; and   irradiating a recording light through the sample to the master, so that at least one portion of the recording light is reflected by the master as an object light carrying the master hologram information, and so that the object light and the recording light are interfered on the photoalignment material layer to produce a duplicated hologram in the photoalignment material layer.   
     
     
         2 . The method according to  claim 1 , further comprising:
 forming a hologram optical element by placing a liquid crystal layer on the sample.   
     
     
         3 . The method according to  claim 2 , wherein forming a hologram optical element by placing a liquid crystal layer on the sample comprises:
 depositing a liquid crystal material after the duplicated hologram is produced in the photoalignment material layer.   
     
     
         4 . The method according to  claim 2 , wherein the liquid crystal layer is a cholesteric liquid crystal layer, and forming a hologram optical element by placing a liquid crystal layer on the sample comprises:
 forming a reflective hologram optical element by placing the cholesteric liquid crystal layer, wherein the cholesteric liquid crystal layer has a helical pitch range from 250 nanometers to 500 nanometers.   
     
     
         5 . The method according to  claim 2 , wherein the liquid crystal layer is a nematic liquid crystal layer, and forming a hologram optical element by placing a liquid crystal layer on the sample comprises:
 forming a transmissive hologram optical element by placing the nematic liquid crystal layer.   
     
     
         6 . The method according to  claim 2 , wherein the liquid crystal layer is a cholesteric liquid crystal layer, and forming a hologram optical element by placing a liquid crystal layer on the sample comprises:
 forming a transmissive hologram optical element by placing the cholesteric liquid crystal layer, wherein the cholesteric liquid crystal layer has a helical pitch larger than 2000 nanometers.   
     
     
         7 . The method according to  claim 1 , wherein the master has a master substrate, a photoalignment layer placed on the substrate and a chiral-doped liquid crystal layer placed on the photoalignment layer. 
     
     
         8 . The method according to  claim 7 , wherein a helical pitch and a thickness of the cholesteric liquid crystal layer are provided so that the master exhibits a diffraction efficiency larger than 80% for the recording light. 
     
     
         9 . The method according to  claim 1 , wherein the recording light and the object light have the same first polarization. 
     
     
         10 . The method according to  claim 9 , wherein the recording light and the object light are circularly polarized light with the same first handedness. 
     
     
         11 . The method according to  claim 1 , wherein the recording light and the object light have the same first polarization. 
     
     
         12 . A hologram optical element manufactured by using a method according to  claim 1 .